docs: def get_mean_and_stddevs(self, sites, rup, dists, imt, stddev_types):
          """
          See :meth:`superclass method
          <.base.GroundShakingIntensityModel.get_mean_and_stddevs>`
          for spec of input and result values.
          """
          # extracting dictionary of coefficients specific to required
          # intensity measure type.
  
          C = self.COEFFS[imt]
          imean = (self._compute_magnitude(rup, C) +
                   self._compute_distance(rup, dists, C) +
                   self._get_site_amplification(sites, C) +
                   self._compute_forearc_backarc_term(C, sites, dists, rup))
  
          istddevs = self._get_stddevs(C,
                                       stddev_types,
                                       num_sites=len(sites.vs30))
  
          # Convert units to g,
          # but only for PGA and SA (not PGV):
          if imt.name in "SA PGA":
              mean = np.log((10.0 ** (imean - 2.0)) / g)
          else:
              # PGV:
              mean = np.log(10.0 ** imean)
          # Return stddevs in terms of natural log scaling
          stddevs = np.log(10.0 ** np.array(istddevs))
          # mean_LogNaturale = np.log((10 ** mean) * 1e-2 / g)
          return mean, stddevs